Answered: More Problems with VEXnet Keys

We’re competing in BEST, and we’ve got a problem getting the cortex and joystick controller to connect after downloading a program. (I’m cross-posting between here, the RobotC forum, and the BEST forum, so if you’re over there too, it’s the same problem.)

Using the cortex 2.0, RobotC version 3.03, all the latest firmware (VEX_cortex_0903.hex, WIFI_RC_2p0_V3_16.BIN, WIFI_OI_2p0_V3.BIN), using the straight USB-to-USB connection, on a Windows XP Service Pack 3 machine with the 32-bit driver (our BEST hub doesn’t supply the USB-to-serial programming cord, though that’s something we plan to buy in the near future). Batteries charged, all the standard basic troubleshooting stuff is good. Download method set to USB only; however, on the RobotC Preferences screen, platform tab, the Communications port drop-down menu lists only automatic selection and several COMM ports (there is no USB option).

After downloading the master CPU and RobotC firmware, the VEXnet link will connect–green lights on the ROBOT, VEXnet, and joystick. But after powering down and removing the VEXnet keys and connecting the USB cable again, and downloading ANY program (not just our custom competition program but the sample RobotC programs as well), powering down and plugging in the VEXnet key and turning the cortex and joystick controller back on again, the cortex and joystick won’t connect over VEXnet.

Repeating the process of reinstalling the firmware (master CPU and RobotC) will restore the ability to connect via VEXnet (once the cortex and joystick controller are re-sync’d via the USB cable), but again, downloading any program results in the VEXnet being unable to connect. With a program downloaded, even in tethered mode (with the VEXnet keys removed and the cortex and joystick controller connected via the USB cable) the two won’t link.

Another issue that we’ve noted (but doesn’t affect us yet, since we can’t get VEXnet to connect with a program downloaded but will once that’s fixed) is that the cortex and joystick controller cannot be calibrated. By using the VEXnet link prior to downloading any program (that is, while the VEXnet link is still operational), and going through the calibration procedure (holding down the 6U button on the joystick controller while simultaneously pressing the recessed CONFIG buttong on the cortex), the cortex/joystick controller won’t enter the calibration mode, which is supposed to be indicated by the joystick light flashing red and green. Ours just sits there staying green, no red at all, despite keeping the 6U and CONFIG buttons depressed for more than 30 seconds.

So . . . what are we doing wrong here?

OK, got an answer from Jesse Flot over on the RobotC forums. It is a RobotC issue; the download method must be set to VEXnet and USB, not to USB only (this is on one of the drop-down menus off the menu bar in RobotC; I’m not on a computer with RobotC installed so I can’t look up which one it is, but if you’re at all familiar with RobotC you should be able to find it).

While we are downloading the program to the cortex via USB only, setting the download method to ‘USB only’ blocks the cortex from connecting to ANYTHING via VEXnet, including the joystick controller. This was not readily apparent from the documentation.

This also fixed the inability to calibrate the joysticks as well.